Redundancy version design solution in communication systems

ABSTRACT

This application discloses an information processing method, an apparatus, a communication device, and a communication system. The communication device is configured to determine a redundancy version transmission sequence, where the redundancy version transmission sequence is used to indicate a sending sequence of a plurality of redundancy versions; determine a transmission number; and obtain a redundancy version from a buffer sequence based on the redundancy version transmission sequence and the transmission number and send the redundancy version. The communication device may be applied to a communication system supporting a plurality of redundancy version transmission sequences, for example, a 5th generation (5G) communication system. Because the redundancy version transmission sequence is determined before data transmission, communication efficiency is improved, and HARQ performance is improved.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2018/108360, filed on Sep. 28, 2018, which claims priority toChinese Patent Application No. 201710911469.4, filed on Sep. 29, 2017.The disclosures of the aforementioned patent applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

Embodiments of the present application relate to communications field,and more specifically, rather than limitation, the embodiments of thepresent application relate to a redundancy version (RV) design forretransmission in a communication system.

BACKGROUND

In a wireless communication system, hybrid automatic repeat request(HARQ) technology is an important technology, and can well improve datalink reliability.

Low-density parity-check (LDPC) codes are a type of linear block codesthat have a sparse parity-check matrix and are featured by a flexiblestructure and low decoding complexity. Because of use of partiallyparallel iteration decoding algorithms, the LDPC codes have higherthroughput rates than conventional Turbo codes. The LDPC codes areconsidered as next-generation error correcting codes for communicationsystems and can be used to improve reliability and power utilization ofchannel transmission. The LDPC codes can be widely applied to spacecommunications, fiber optic communications, personal communicationsystems, ADSLs (Asymmetric Digital Subscriber Lines), magnetic recordingdevices, and the like. Currently, in fifth generation (5G) mobilecommunication systems, it is already considered to use the LDPC codes asone of channel coding schemes.

To support different code lengths and code rates, a communication deviceperforms rate matching after channel coding to adjust a code rate of acoded block, and obtains a bit sequence that needs to be sent to match adecoding code rate. During the rate matching, the communication devicemay further perform bit puncturing on an LDPC code block generated afterencoding, to increase the code rate; or during the rate matching,perform bit repetition on an LDPC code block generated after encoding,to decrease the code rate.

During the rate matching, a communication device at a transmit endselects a bit sequence that needs to be sent, and sends the bit sequenceto a communication device at a receive end after such processing asinterleaving and mapping etc. The communication device at the receiveend combines soft values of the bit sequence with stored soft value bits(soft channel bit) for decoding, to obtain a code block.

When the communication device uses an existing rate matching method fora bit sequence encoded by using the LDPC code, HARQ performance isrelatively poor.

SUMMARY

Embodiments of the present application provide an information processingmethod, an apparatus, a communication device, and a communicationsystem, to improve HARQ performance.

According to a first aspect, an information processing method in acommunication system is provided. The method includes:

determining a redundancy version sequence, where the redundancy versionsequence is used to indicate a transmitting order of a plurality ofredundancy versions;

determining a transmission number; and

obtaining a redundancy version from a buffer sequence based on theredundancy version sequence and the transmission number, and sending theredundancy version.

In a possible implementation, the method further includes:

sending information indicating the redundancy version sequence.

According to a second aspect, an information processing method in acommunication system is provided. The method includes:

determining a redundancy version sequence, where the redundancy versionsequence is used to indicate an order of sending a plurality ofredundancy versions;

determining a transmission number; and

combining received redundancy versions in a buffer sequence based on theredundancy version sequence and the transmission number.

Optionally, the method further includes: performing LDPC decoding on thebuffer sequence.

In a possible implementation of the second aspect, informationindicating the redundancy version sequence may be received, and theredundancy version sequence may be determined based on the informationindicating the redundancy version sequence.

Based on the foregoing aspects or the foregoing possibleimplementations, in another possible implementation, the redundancyversion sequence may be determined based on at least one of thefollowing factors: a service type, a transmission mode, or atransmission code rate;

the service type includes at least one of the following: eMBB, URLLC,mMTC, VoNR, or the like; and

the transmission mode includes at least one of the following: grantfree, multislot aggregation, or the like.

The foregoing factors may be each used as a transmission scenario, ormay be combined to obtain a transmission scenario, and a redundancyversion sequence that can match performance of a correspondingtransmission scenario is obtained based on the scenario, therebyimproving HARQ performance.

In a design, if the service type is eMBB, the redundancy versionsequence is indicated by a sequence of redundancy version numbers as {0,2, 3, 1} or {0, 3, 2, 1}.

In another design, if the service type is URLLC, the redundancy versionsequence is indicated by a sequence of redundancy version numbers as {0,3, 2, 1} or {0, 3, 0, 3}.

In another design, if the transmission mode is grant free or multislotaggregation, the redundancy version sequence is indicated by a sequenceof redundancy version numbers as {0, 3, 0, 3}.

It may be understood that, the foregoing designs may be separatelyapplied, or may be applied in a combined manner.

In a possible design of the foregoing aspects or the foregoingimplementations, the plurality of redundancy versions each are aself-decodable redundancy version. For example, the redundancy versionsequence may be one of the following: {0, 3, 0, 3}, {0, 3, 3, 3}, {0, 0,3, 3}, {0, 3, 3, 0}, {0, 0, 0, 3}, {0, 0, 0, 0}, or {3, 3, 3, 3}.

Because there are at least two self-decodable redundancy versions in bitsequences during a plurality of retransmissions, a decoding success rateis improved, and a quantity of retransmissions is reduced.

Based on the foregoing aspects or the foregoing possibleimplementations, in another possible design, the redundancy versionsequence may be one of the following: {0, 3, 0, 3}, {0, 3, 3, 3}, {0, 0,3, 3}, {0, 3, 3, 0}, {0, 0, 0, 3}, {0, 0, 0, 0}, {3, 3, 3, 3}, {0, 2, 3,1}, or {0, 3, 2, 1}.

In a possible design of the foregoing aspects, the informationindicating the redundancy version sequence is sent on a downlink controlchannel or a downlink data channel. For example, the informationindicating the redundancy version sequence is carried by a physicallayer signaling or RRC signaling and sent on the downlink controlchannel or the downlink data channel.

If a base graph of an LDPC code is BG1, four corresponding startingpositions are respectively {0z, 17z, 33z, 56z}. Correspondingly,

a redundancy version 0 is a bit sequence obtained from bit 0z in abuffer sequence W;

a redundancy version 1 is a bit sequence obtained from bit 17z in thebuffer sequence W;

a redundancy version 2 is a bit sequence obtained from bit 33z in thebuffer sequence W; and

a redundancy version 3 is a bit sequence obtained from bit 56z in thebuffer sequence W.

If a base graph of an LDPC code is BG2, four corresponding startingpositions are respectively {0z, 13z, 25z, 43z}. Correspondingly,

a redundancy version 0 is a bit sequence obtained from bit 0z in abuffer sequence W;

a redundancy version 1 is a bit sequence obtained from bit 13z in thebuffer sequence W;

a redundancy version 2 is a bit sequence obtained from bit 25z in thebuffer sequence W; and

a redundancy version 3 is a bit sequence obtained from bit 43z in thebuffer sequence W.

In a possible design, the redundancy version number keeps consistentwith a number rv_(idx) of the starting position.

Optionally, the redundancy version sequence may be indicated by asequence of numbers of starting positions; or may be indicated by asequence of starting positions; or may be indicated by the redundancyversion number sequence. In this manner, each redundancy versionsequence is identified by one number. The information used to indicatethe redundancy version order may include the sequence of the numbers ofthe starting positions, or the sequence of the starting positions, orthe redundancy version number sequence.

According to a third aspect, a communication apparatus is provided. Thecommunication apparatus may include corresponding modules configured toperform any one of the possible implementations of the first aspect inthe foregoing method designs. The modules may be software and/orhardware.

In a possible design, the communication apparatus according to the thirdaspect includes a processing unit, configured to determine a redundancyversion sequence and a transmission number; an obtaining unit,configured to obtain a redundancy version from a buffer sequence basedon the redundancy version sequence and the transmission number; and atransceiver unit, configured to send the redundancy version.

The apparatus may be configured to perform the method according to anyone of the possible implementations of the first aspect. For details,refer to the descriptions of the foregoing aspect.

In a possible design, the processing unit and the obtaining unit may beone or more processors, and may control the transceiver unit to sendinformation indicating the redundancy version sequence.

The transceiver unit is configured to input/output a signal, forexample, configured to output a signal corresponding to an output bitsequence, and optionally, may further send the information indicatingthe redundancy version sequence.

The transceiver unit may be a transceiver, or may be an input/outputcircuit or a communication interface. For example, the communicationapparatus may be a terminal or a base station or a network device, andthe transceiver unit of the communication apparatus may be atransceiver. The communication apparatus may alternatively be a chip,and a transceiver component of the communication apparatus may be aninput/output circuit of the chip.

According to a fourth aspect, a communication apparatus is provided. Thecommunication apparatus may include corresponding modules configured toperform any one of the possible implementations of the second aspect inthe foregoing method designs. The modules may be software and/orhardware.

In a possible design, the communication apparatus according to thefourth aspect includes:

a determining unit, configured to determine a redundancy versionsequence and a transmission number; and

a processing unit, configured to combine received redundancy versions ina buffer sequence based on the redundancy version sequence and thetransmission number.

Optionally, the processing unit may be further configured to performLDPC decoding on the buffer sequence.

The apparatus may be configured to perform the method according to anyone of the possible implementations of the second aspect. For details,refer to the descriptions of the foregoing aspect.

In a possible design, the processing unit and the determining unit maybe one or more processors.

Optionally, the apparatus may further include a transceiver unit,configured to: receive information indicating the redundancy versionsequence and receive a signal including a redundancy version of a buffersequence W.

The transceiver unit is configured to input/output a signal, forexample, configured to receive a signal including a soft bit sequence.

The transceiver unit may be a transceiver, or may be an input/outputcircuit or a communication interface. For example, the communicationapparatus may be a terminal or a base station or a network device, andthe transceiver unit of the communication apparatus may be atransceiver. The communication apparatus may alternatively be a chip,and a transceiver component of the communication apparatus may be aninput/output circuit of the chip.

According to a fifth aspect, a communication apparatus is provided. Thecommunication apparatus includes one or more processors.

In a possible design, the one or more processors may be configured toimplement a function according to any one of the first aspect or theimplementations of the first aspect. Optionally, the processor may befurther configured to implement another function in addition to thefunction according to any one of the first aspect or the implementationsof the first aspect.

In a possible design, the one or more processors may be configured toimplement a function according to any one of the second aspect or theimplementations of the second aspect. Optionally, the processor may befurther configured to implement another function in addition to thefunction according to any one of the second aspect or theimplementations of the second aspect.

Optionally, the communication apparatus according to the fifth aspectmay further include a transceiver and an antenna.

Optionally, the communication apparatus according to the third aspect tothe fifth aspect may further include a component configured to generatea transport block CRC, a component used for code block segmentation andCRC check, an encoder, an interleaver used for interleaving, a modulatorused for modulation processing, or the like. In a possible design,functions of these components may be implemented by the one or moreprocessors.

Optionally, the communication apparatus according to the third aspect tothe fifth aspect may further include a demodulator configured to performa demodulation operation, a de-interleaver used for de-interleaving, adecoder, or the like. In a possible design, functions of thesecomponents may be implemented by the one or more processors.

According to a sixth aspect, an embodiment of the present applicationprovides a communication system. The system includes the communicationapparatus according to any one of the third aspect to the fifth aspect.

According to another aspect, an embodiment of the present applicationprovides a computer storage medium. The computer storage medium stores aprogram, and when the program is run, a computer is enabled to performthe methods according to the foregoing aspects.

According to still another aspect of this application, a computerprogram product including an instruction is provided. When theinstruction is run on a computer, the computer is enabled to perform themethods according to the foregoing aspects.

According to the information processing method, the apparatus, thecommunication device, and the communication system in the embodiments ofthe present application, HARQ performance can be improved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1-1 is a base graph of an LDPC code;

FIG. 1-2 is another base graph of an LDPC code;

FIG. 2 is a structural diagram of a communication system according to anembodiment of the present application;

FIG. 3 is a flowchart of an information processing method according tosome embodiments of the present application;

FIG. 4 is a flowchart of an information processing method according tosome embodiments of the present application; and

FIG. 5 is a structural diagram of an information processing apparatusaccording to some embodiments of the present application.

DESCRIPTION OF EMBODIMENTS

For ease of understanding, some nouns involved in this application aredescribed below.

In this application, nouns “network” and “system” are ofteninterchangeably used, and “apparatus” and “device” are also ofteninterchangeably used, meanings of which are conventionally understood. A“communication apparatus” may be a microchip (such as a baseband chip, adigital signal processing chip, or a general-purpose chip), a terminal,a base station, or another network device.

A terminal is a device having a communication function, and may includea handheld device, an in-vehicle device, a wearable device, a computingdevice, another processing device connected to a wireless modem, or thelike that has a wireless communication function. The terminal may bedeployed on land, including an indoor or outdoor device, a handhelddevice, or an in-vehicle device; or may be deployed on water (forexample, on a vessel); or may be deployed in air (for example, on an airplane, a balloon, or a satellite). The terminal may be a mobile phone, atablet computer (such as a Pad), a computer having a wirelesssending/receiving function, a virtual reality (VR) terminal device, anaugmented reality (AR) terminal device, a wireless terminal inindustrial control, a wireless terminal in self driving scheme, awireless terminal in remote medical scheme, a wireless terminal in asmart grid scheme, a wireless terminal in transportation safety scheme,a wireless terminal in a smart city scheme, a wireless terminal in asmart home scheme, and the like. The terminal may have different namesin different networks, for example, user equipment, a mobile console, asubscriber unit, a station, a cellular phone, a personal digitalassistant, a wireless modem, a wireless communication device, a handhelddevice, a laptop computer, a cordless phone, and a wireless local loopstation. For ease of description, these devices are simply referred toas the terminal in this application.

Abase station (BS) may also be referred to as a base station device, andis a device deployed in a radio access network to provide a wirelesscommunication function. The base station may have different names indifferent radio access systems. For example, in a universal mobiletelecommunication system (UMTS) network, the base station is referred toas a NodeB (NodeB); in an LTE network, the base station is referred toas an evolved NodeB (eNB or eNodeB); in a new radio (NR) network, thebase station is referred to as a transmission reception point (TRP) or anext-generation NodeB (gNB); or in a network integrating a plurality ofother technologies or in other evolved networks, the base station mayhave other names. The present application is not limited thereto.

The following describes the technical solutions in the embodiments ofthe present application with reference to the accompanying drawings inthe embodiments of the present application.

An LDPC code may be used by a communication system to perform encoding.For example, in a 5G system, the LDPC code is for data encoding. TheLDPC code may be usually presented by using a parity check matrix H. Theparity check matrix H of the LDPC code may be obtained by using a basegraph and a shift value. The base graph may usually include m*n matrixelements (entries), and may be indicated in a form of a matrix with mrows and n columns. A value of a matrix element is either 0 or 1. Anelement having a value of 0 is sometimes also referred to as a zeroelement, and it indicates that the element can be replaced by a z*zall-zero matrix. An element having a value of 1 is sometimes alsoreferred to as a non-zero element, and it indicates that the element canbe replaced by a z*z circular permutation matrix. In other words, eachmatrix element indicates either an all-zero matrix or a circularpermutation matrix. FIG. 1-1 and FIG. 1-2 provide examples of two basegraphs of the LDPC code. A size of BG1 shown in FIG. 1-1 is 46 rows and68 columns. A size of BG2 shown in FIG. 1-2 is 42 rows and 52 columns.In the base graph shown in the foregoing figure, a row index is markedon the leftmost column, and a column index is marked on the uppermostcolumn. Only non-zero elements are shown in each column and row, and areindicated by “1”, and a blank part is a zero element. The column 0 andthe column 1 are columns of built-in puncture bits which are not writteninto a circular buffer.

If an element in row i and column j in the base graph has a value of 1and a shift value of P_(i,j), where P_(i,j) is an integer greater thanor equal to 0, it indicates that the element having the value of 1 inthe row i and the column j may be replaced by a z*z circular permutationmatrix corresponding to P_(i,j) and the circular permutation matrix maybe obtained by circularly shifting an identity matrix of size z*z to theright P_(i,j) times. It can be learned that each element having a valueof 0 in the base graph is replaced by a z*z all-zero matrix, and eachelement having a value of 1 is replaced by a z*z circular permutationmatrix corresponding to a shift value of the element, so that the paritycheck matrix of the LDPC code can be obtained. z is a positive integerand may also be referred to as a lifting size, and may be determinedbased on a code block size that are supported by a system and aninformation data size. It can be learned that a size of the parity checkmatrix H is (m*z)*(n*z).

Value of P_(i,j) may depend on the lifting size z, for an element havinga value of 1 at a same position in the matrix, P_(i,j) may be differentfor different lifting sizes Z. For ease of implementation, usually, anm*n base matrix (parity check matrix) is further defined in the system.And a position of each element in the base matrix is in a one-to-onecorrespondence with a position of each element in the base graph. A zeroelement in the base graph has a same position in the base matrix and isindicated by −1 or null, and a non-zero element having a value of 1 atthe row i and the column j in the base graph have a same position in thebase matrix and may be indicated by P_(i,j). P_(i,j) is a positiveinteger greater than or equal to 0. In this embodiment of thisapplication, the base matrix is sometimes referred to as a shift matrixof a base graph.

In the communication system, information data is transmitted betweencommunication devices (for example, a base station or a terminal).Because a wireless transmission environment is complex, variable, andeasily interfered, an error easily occurs. To reliably send informationdata, a communication device at a transmit end performs processing suchas CRC check, channel coding, rate matching, and interleaving on theinformation data, maps interleaved coded bits into modulated symbols,and sends the modulated symbols to a communication device at a receiveend. After receiving the modulated symbols, the receiving devicerestores the modulated symbols into the information data bycorrespondingly performing de-interleaving, rate de-matching, decoding,and CRC check. In these processes, transmission errors can be reducedand reliability of data transmission can be improved.

A communication system 200 shown in FIG. 2 may be widely applied todifferent types of communication such as speech communication and datacommunication. The communication system may include a plurality ofwireless communication devices. For clarity, FIG. 2 shows only acommunication device 20 and a communication device 21. Controlinformation or data information is received and sent between thecommunication device 20 and the communication device 21 as aninformation sequence. In a possible design, the communication device 20as a communication device at a transmit end performs LDPC encodingprocessing on a bit sequence C of a length of K. The bit sequence C maybe a bit sequence of control or data information to be sent by thecommunication device 20, or is obtained by performing at least codeblock segmentation processing on the bit sequence. The bit sequence Chaving a length of K may further include cyclic check bits and mayfurther include filling bits.

In a possible implementation, the communication device 20 determines,based on the length K of the bit sequence C, an LDPC matrix used forencoding. For example, the communication device 20 may determine alifting size z based on K, and then perform lifting on a base matrix ofa corresponding code rate based on z to obtain an LDPC matrix. Anencoded bit sequence (i.e. a coded block) may be obtained by encodingthe bit sequence C by using the LDPC matrix. If shortening is notperformed, a bit sequence D may be the encoded bit sequence; or if ashortening operation is performed on the encoded bit sequence, that is,s₀ bits are shortened from the bit sequence, for example, s₀ bits aredeleted from the encoded bit sequence, the bit sequence D may be a bitsequence obtained by shortening s₀ bits from the encoded bit sequence.s₀ is an integer greater than or equal to 0. For example, s₀=n·r, n is apositive integer, and r is a quantity of bits included in a unit bitsegment in a buffer sequence W. The unit bit segment reflects agranularity of starting positions that are set in the buffer sequence W.For example, the starting positions may be set in the buffer sequence Wbased on an integer multiple of the lifting size, that is, a quantity rof bits included in the unit bit segment is equal to z. For anotherexample, before the bit sequence D enters the buffer sequence W,interleaving needs to be performed on the bit sequence D. If a quantityof columns of an interleaving matrix is C_(subblock), a quantity of rowsof the interleaving matrix is R_(subblock). R_(subblock) is a minimuminteger satisfying K_(D)≤C_(subblock)·R_(subblock), and the quantity rof bits included in the unit bit segment may be R_(subblock). That is,the starting positions may be set based on an integer multiple ofR_(subblock). A length of the bit sequence D is K_(D). The bit sequenceD may include a plurality of bits in the bit sequence C, and may furtherinclude one or more parity bits, and a bit in the bit sequence C issometimes also referred to as an information bit or a systematic bit inthe bit sequence D. In the present application, the bit sequence D issometimes also referred to as a coded block. Each coded block includesinformation bits and parity bits. The information bits may includefilling bit(s). If the information bits includes a filling bit, thefilling bit is usually indicated by “null”.

A coded block or a coded block on which bit reordering is performed isstored in a circular buffer of the communication device 20, and thecommunication device 20 obtains a plurality of output bits sequentiallyfrom the coded block stored in the circular buffer, to obtain an outputbit sequence. An output bit is a bit other than a filling bit in thecoded block, so that the output bit sequence does not include anyfilling bit. The output bit sequence is sent after being interleaved andmapped into modulated symbols. When retransmission occurs, thecommunication device 20 selects another output bit sequence from thecoded block stored in the circular buffer for sending. If the output bitobtained sequentially reaches the last bit of the circular buffer, anoutput bit is continuously selected from bit 1 of the circular buffer.An output bit sequence selected from a coded block in the circularbuffer may also be referred to as a redundancy version (rv) of the codedblock.

After demodulating and de-interleaving the received modulated symbol,the communication device 21 stores soft values of the received outputbit sequence in a corresponding position in a soft information buffer(soft buffer). If retransmission occurs, the communication device 21combines soft values of output bit sequences during all retransmissionsand stores the combined soft values in the soft information buffer.Combination herein means that if two output bits received at twodifferent times are at the same positions, soft values of the two outputbits received at two different times are combined. In a design,positions in the soft information buffer in the communication device 21are in a one-to-one correspondence with positions of coded blocks in thecircular buffer in the communication device 20. That is, if the positionof the output bit in the coded block in the circular buffer of thecommunication device 20 is bit p, the position of the soft value of theoutput bit in the soft information buffer of the communication device 21is also bit p.

The communication device 21 decodes all soft values in the softinformation buffer to obtain a code block of an information sequence.Because the communication device 21 may obtain a transport block size,the communication device 21 may determine a quantity of code blocks intowhich one transport block is segmented and a length of each code block.If a code block includes a CRC bit segment, the communication device 21may further check the code block by using the CRC bit segment. Thecommunication device 21 concatenates all code blocks into one transportblock, and further checks and concatenates the transport block withothers to finally obtain the information sequence. It can be learnedthat the communication device 21 performs an inverse process of aninformation processing method of the communication device 20.

It should be noted that, herein, a process of receiving and sending theinformation sequence between the communication device 20 and thecommunication device 21 is merely an example. Division of these modulesis merely an example, and some modules may be optional according to asystem design requirement, or functions of some modules may be combinedand performed in one module. This is not limited. In addition, thesemodules may be implemented by using software, or hardware, or acombination of software and hardware, for example, may be implemented byone or more processors. The present application is not limited thereto.

It should be noted that, in various embodiments of the presentapplication, the communication device 20 may be a network device such asa base station in the communication system, and the correspondingcommunication device 21 may be a terminal. The communication device 20may alternatively be a terminal in the communication system, andcorrespondingly, the communication device 21 may be a network devicesuch as a base station in the communication system. The communicationdevice 20 and the communication device 21 may alternatively be chips,for example, the modules in the foregoing processing process may beimplemented by the one or more processors.

FIG. 3 is a schematic flowchart of an information processing methodaccording to an embodiment of the present application. The method may beapplied to a communication system. The communication system includes acommunication device 20 and a communication device 21. The method may beimplemented by the communication device 20 and includes the followingsteps.

301: Determine a redundancy version sequence.

The redundancy version sequence is used to indicate a sequence ofsending a plurality of redundancy versions.

The foregoing bit sequence D of the coded block is used as an example.The communication device 20 may determine an output bit sequence basedon the bit sequence D or a part of the bit sequence D. When supportingretransmission, the communication device may determine, based on the bitsequence D or the part of the bit sequence D, an output bit sequenceduring each transmission.

In a possible design, a buffer sequence W having a length of N_(CB) mayinclude the bit sequence D or the part of the bit sequence D, and thebuffer sequence including each bit is an LDPC code.

In a possible implementation, the buffer sequence W may include all bitsin the bit sequence D. For example, the buffer sequence W may includethe bit sequence D. For another example, the buffer sequence W mayinclude the bit sequence D on which at least interleaving processing hasbeen performed. For another example, the buffer sequence may include thebit sequence D on which at least filling processing has been performed.For another example, the buffer sequence may include the bit sequence Don which at least interleaving processing and filling processing havebeen performed.

In another possible implementation, the buffer sequence W may includesome bits in the bit sequence D. For example, the length of the bitsequence D exceeds a maximum length of the buffer sequence W, andtherefore, the buffer sequence W can include only some bits in the bitsequence D. Similarly, the buffer sequence W may include some bits inthe bit sequence D. For another example, the buffer sequence W mayinclude some bits in the bit sequence D on which at least interleavingprocessing has been performed. For another example, the buffer sequencemay include some bits in the bit sequence D on which at least fillingprocessing has been performed. For another example, the buffer sequencemay include some bits in the bit sequence D on which at leastinterleaving processing and filling processing have been performed.

The buffer sequence W may also be referred to as a circular buffer. Wheninitial transmission or retransmission is performed, the communicationdevice 20 determines an output bit sequence for the initial transmissionor the retransmission in the bit sequence stored in the circular buffer.For ease of description, transmission i indicates the initialtransmission or the retransmission. When i=0, it indicates the initialtransmission, or when i>0, it indicates the retransmission, where i isan integer. For example, when i=1, it indicates the firstretransmission, or when i=2, it indicates the second retransmission. Anupper limit of retransmissions depends on a maximum quantity ofretransmissions in a system. An output bit sequence for each initialtransmission or retransmission may be a redundancy version of the bitsequence D.

In a possible design, k_(max) starting positions may be fixedly set inthe buffer sequence W, where k_(max) is an integer greater than or equalto 4. Each starting position may be indicated by a number, namely, anindex (index), for example, indicated by rv_(idx), and0≤rv_(idx)<k_(max). For example, k_(max)=4, and values of numbersrv_(idx) of four starting positions are respectively one of 0, 1, 2, or3.

An output bit sequence during each transmission may be obtained from oneof k_(max) starting positions in the buffer sequence W. If there arek_(max) starting positions, k_(max) redundancy versions may be obtained.Each redundancy version may correspond to the number rv_(idx) of thestarting position in the buffer sequence W.

An example in which k_(max)=4 is used for description below. In otherwords, four redundancy versions may be obtained from the buffer sequenceW. It may be understood that, the present application is not limitedthereto, and k_(max) may also be another value.

An example in which a base graph of an LDPC code is BG1 shown in FIG.1-1 is used. A bit position starts to be numbered from 0, and thestarting position may be an integer multiple of a lifting size. Aredundancy version 0 is a bit sequence obtained from a position withrv_(idx)=0, namely, bit 0z in the buffer sequence W. A redundancyversion 1 is a bit sequence obtained from a position with rv_(idx)=1,namely, bit 17z in the buffer sequence W. A redundancy version 2 is abit sequence obtained from a position with rv_(idx)=2, namely, bit 33zin the buffer sequence W. Redundancy version 3 is a bit sequenceobtained from a position with rv_(idx)=3, namely, bit 56z in the buffersequence W. Redundancy version number may alternatively be indicated byrv_(idx) sometimes. It may be understood that, a position of the bit 0zis a bit with a position number of 0; the bit 17z is a bit with aposition number of 17z; the bit 33z is a bit with a position number of33z; and the rest can be deduced by analogy. Details are not describedagain below.

Systematic bits and parity bits included in output bit sequencesobtained from different starting positions have different compositions.Redundancy version 0 includes a relatively large quantity of systematicbits, and if there is no interference or loss in a receiving process,redundancy version 0 can be usually decoded independently, that is,redundancy version 0 is a self-decodable redundancy version. Redundancyversion 3 also includes a relatively large quantity of systematic bitsand can also be decoded independently, and is a self-decodableredundancy version. However, the redundancy versions 1 and 2 mainlyinclude parity bits and a small quantity of systematic bits, and are notself-decodable, but combined decoding can be performed on the redundancyversions 1 and 2 with a self-decodable redundancy version, and acombined bit sequence is used as an LDPC code, and has a low equivalentcode rate, thereby reducing decoding complexity.

When bits in the buffer sequence W are transmitted one time or aplurality of times, corresponding redundancy versions are usuallyobtained sequentially based on the redundancy version sequence, and aretransmitted. The redundancy version sequence may be indicated by asequence of numbers of redundancy versions, or may be indicated by asequence of starting positions of output bit sequences during alltransmissions in the buffer sequence W or a sequence of numbers of thestarting positions. The present application is not limited thereto. Fortransmission i, a corresponding starting position is determined based onthe redundancy version sequence, and an output bit sequence rv(i) thatmay also be referred to as a to-be-sent redundancy version is obtainedfrom the starting position in the buffer sequence W.

In a design, an sequence of starting positions may be circulated basedon {0, 2, 3, 1}. In this design, during the initial transmission,redundancy version 0 is obtained from starting position 0; during thefirst retransmission, redundancy version 2 is obtained from startingposition 2; during the second retransmission, redundancy version 3 isobtained from starting position 3; during the third retransmission,redundancy version 1 is obtained from starting position 1; during thefourth retransmission, redundancy version 0 is obtained from startingposition 0; and the rest can be deduced by analogy.

An example in which encoding is performed based on an LDPC code (matrix)whose base graph is BG1 is used. In the base graph, column 0 to column21 correspond to coded bits of information bits, and the rest columnscorrespond to coded bits of parity bits. Coded bits corresponding to twocolumns of built-in puncture bits, namely, column 0 and column 1, do notenter the circular buffer, thus the buffer sequence W is 66z,corresponding starting positions are {0z, 17z, 33z, 56z}, andcorrespondences between rv_(idx) and the starting positions are shown inTable 1:

TABLE 1 Starting position Starting number rv_(idx) position 0  0z 1 17z2 33z 3 56z

When rv_(idx) is 0 or 3, an obtained output bit sequence includes arelatively large quantity of coded bits of information bits, that is,when the starting position in the buffer sequence W is bit 0 or bit 56z,an obtained output bit sequence includes a relatively large quantity ofcoded bits of information bits and is self-decodable.

When rv_(idx) is 1 or 2, an obtained output bit sequence includes arelatively large quantity of parity bits, that is, when the startingposition in the buffer sequence W is bit 17z or bit 33z, an obtainedoutput bit sequence includes a relatively large quantity of parity bitsand is not self-decodable, and the output bit sequence needs to becombined with a self-decodable redundancy version for decoding.

An example in which encoding is performed based on an LDPC code (matrix)whose base graph is BG2 is used. In the base graph, column 0 to column 9correspond to coded bits of information bits, and the rest columnscorrespond to coded bits of parity bits. Coded bits corresponding to twocolumns of built-in puncture bits, namely, the column 0 and the column1, do not enter the circular buffer, thus the buffer sequence W is 50z,corresponding starting positions are {0z, 13z, 25z, 43z}, andcorrespondences between rv_(idx) and the starting positions are shown inTable 2:

TABLE 2 Starting position Starting number rv_(idx) position 0  0z 1 13z2 25z 3 43z

When rv_(idx) is 0 or 3, an obtained output bit sequence includes arelatively large quantity of coded bits of information bits, that is,when the starting position in the buffer sequence W is bit 0 or bit 43z,an obtained output bit sequence includes a relatively large quantity ofcoded bits of information bits and is self-decodable.

When rv_(idx) is 1 or 2, an obtained output bit sequence includes arelatively large quantity of parity bits, that is, when the startingposition in the buffer sequence W is bit 13z or bit 25z, an obtainedoutput bit sequence includes a relatively large quantity of parity bitsand is not self-decodable, and the output bit sequence needs to becombined with a self-decodable redundancy version for decoding.

In a possible design, the plurality of redundancy versions in theredundancy version sequence may each be a self-decodable redundancyversion. For example, an example in which the redundancy versionsequence is indicated by a sequence of redundancy version numbers isused, and the redundancy version sequence may be one of the following:{0, 3, 0, 3}, {0, 3, 3, 3}, {0, 0, 3, 3}, {0, 3, 3, 0}, {0, 0, 0, 3},{0, 0, 0, 0} or {3, 3, 3, 3}.

In another possible design, for example, the redundancy version sequenceis indicated by a sequence of redundancy version numbers, and theredundancy version sequence may be one of the following: {0, 3, 0, 3},{0, 3, 3, 3}, {0, 0, 3, 3}, {0, 3, 3, 0}, {0, 0, 0, 3}, {0, 0, 0, 0},{3, 3, 3, 3}, {0, 2, 3, 1}, or {0, 3, 2, 1}.

It should be noted that, in the sequences in the foregoing examples, thenumbers may alternatively be replaced by corresponding startingpositions for indication.

In a possible implementation, rv_(idx) of an output bit sequence of eachtransmission loops in a sequence of 0 and 3 in the buffer sequence W. Ifthe base graph of the LDPC matrix is BG1, the starting position loops ina sequence of 0z and 56z, or if the base graph of the LDPC matrix isBG2, the starting positions loops in a sequence of 0z and 43z. In thismanner, because the redundancy version for each transmission isself-decodable, even if packet losses occur a plurality of times, aremaining redundancy version can also be self-decodable. In theforegoing manner of retransmitting a plurality of self-decodableredundancy versions, for a scenario with stable transmission and a smallpacket loss probability, once retransmission occurs, an equivalent coderate of a codeword obtained by combining redundancy versions received bya communication device at a receive end is relatively high, leading torelatively poor decoding performance. Optionally, in a packetloss-sensitive scenario, for example, in a grant free transmission modeor multislot aggregation mode, an output bit sequence during eachtransmission is obtained in the foregoing manner. In the grant freemode, a communication device at a transmit end has no uniquely specifiedair interface physical resource for data sending, and all communicationdevices at the transmit end perform contention-based sending in aresource pool. Consequently, a conflict occurs, and there is arelatively high possibility of being subject to strong interference. Forexample, if the initial transmission is subject to strong interference,the communication device at the receive end cannot implement IR-HARQcombination, and if there is a self-decodable redundancy version in thefirst retransmission, decoding can be completed by using a retransmittedredundancy version, thereby reducing a quantity of retransmissions,reducing an air interface delay, and saving resources.

In another possible implementation, starting position number of anoutput bit sequence of each transmission in the buffer sequence W mayloop in a sequence of 0, 2, 3, and 1. If the base graph of the LDPCmatrix is BG1, the starting position loops in a sequence of 0z, 33z,56z, and 17z, or if the base graph of the LDPC matrix is BG2, thestarting position loops in a sequence of 0z, 25z, 43z, and 13z. If nopacket loss occurs during the initial transmission, the redundancyversion for the initial transmission is self-decodable, or if theredundancy version for the initial transmission is lost, decoding can becompleted only in at least the second retransmission, but an equivalentcode rate of a codeword obtained by combining the redundancy versionsfor the first retransmission and the second retransmission is relativelylow, and comprehensive decoding performance is relatively good. Thepossible implementation is applicable to most enhanced mobile broadband(eMBB) scenarios.

In another possible implementation, a starting position of an output bitsequence in the buffer sequence W may loop in a sequence of 0, 3, 2,and 1. If the base graph of the LDPC matrix is BG1, the startingposition loops in a sequence of 0z, 56z, 33z, and 17z, or if the basegraph of the LDPC matrix is BG2, the starting position loops in asequence of 0z, 43z, 25z, and 13z. In this manner, if a packet lossoccurs during the initial transmission, a self-decodable redundancyversion is included during the first retransmission. Similarly, when atleast two retransmissions occur, performance is the same as that of theprevious implementation, and comprehensive decoding performance isrelatively good. The possible implementation is also applicable to mosteMBB and ultra-reliable and low latency communication (URLLC) scenarios.

In another possible design, the redundancy version sequence may beobtained based on a data transmission scenario. The redundancy versionsequence indicates a sequence of sending a plurality of redundancyversions in the buffer sequence W, and a redundancy version for eachdata transmission may be determined based on the redundancy versionsequence. The data transmission scenario may be determined based on atleast one of the following factors, that is, the redundancy versionsequence may be determined based on one or more of the followingfactors: a service type, a transmission mode, a transmission code rate,or the like. The service type may include eMBB, URLLC, voice over newradio (VoNR), massive machine type communication (mMTC), or the like.The transmission mode may include grant free, multislot (slot)aggregation, or the like. The service type and the transmission mode maybe further combined, for example, eMBB service transmission in grantfree mode or URLLC service transmission in multislot aggregation. Itshould be noted that, this is merely an example herein, and the presentapplication is not limited thereto.

For example, if the service type is eMBB, the redundancy versionsequence may be {0, 2, 3, 1} or {0, 3, 2, 1}.

For another example, if the service type is URLLC, the redundancyversion sequence may be {0, 3, 2, 1} or {0, 3, 0, 3}.

For another example, if the transmission mode is grant free or multislotaggregation, the redundancy version sequence may be {0, 3, 0, 3}.

Because redundancy version configuration information may be determinedbased on the data transmission scenario, if the data transmissionscenario is determined, the redundancy version sequence is alsodetermined. For example, redundancy version sequences of differentservice types and/or in different transmission modes may be configured,predefined, or specified in a protocol. For example, if a service typeof data transmission between the communication device 20 and thecommunication device 21 is eMBB, a sequence of {0, 2, 3, 1} may beselected as an sequence of starting positions of redundancy versions.For another example, if a service type of data transmission between thecommunication device 20 and the communication device 21 is URLLC, asequence of 0, 3, 2, and 1 may be selected as a sequence of startingpositions of redundancy versions. For another example, when thetransmission mode is grant free or multislot aggregation, a sequence of0, 3, 0, and 3 may be selected. Certainly, the redundancy versionconfiguration information may be determined with reference to theservice type and the transmission mode, and the redundancy versionsequence may be further determined based on a factor such as channeltransmission quality. These are merely examples for description herein,and the present application is not limited thereto.

302: Determine a transmission number.

303: Obtain a redundancy version from a buffer sequence based on theredundancy version sequence determined in step 301 and the transmissionnumber determined in step 302, and send the redundancy version.

The communication device 20 may determine a redundancy version for eachtransmission based on the redundancy version sequence obtained from step301, obtain an output bit sequence during each transmission from thebuffer sequence W based on a starting position of the redundancyversion, as a redundancy version, and send the redundancy version to thecommunication device 21.

For example, a BG1 base graph and a sequence of {0, 3, 0, 3} are used asan example, after the communication device 20 sends an output bitsequence that is obtained from the bit 0 in the buffer sequence W duringthe initial transmission, namely, the 0^(th) transmission, that is, thetransmission number is 1, the communication device 20 receives anegative acknowledgment (NACK) from the communication device 21, so thatthe communication device 20 obtains an output bit sequence during thefirst retransmission (that is, the transmission number is 2) from thebit 56z in the buffer sequence W, that is, determines a redundancyversion rv(1). The communication device 20 sends the output bit sequencerv(1) to the communication device 21. If the communication device 20receives a NACK from the communication device 21, the communicationdevice 20 obtains an output bit sequence during the secondretransmission from the bit 0z in the buffer sequence W, that is,determines a redundancy version rv(2). The rest can be deduced byanalogy. When a maximum quantity of retransmissions is reached or aretransmission timer expires, or the communication device 20 receives apositive acknowledgement (ACK) from the communication device 21, thecommunication device may end retransmission. Certainly, thecommunication device 20 may perform a plurality of retransmissionswithout considering a NACK or an ACK from the communication device 21.

During decoding, the communication device 21 at the receive end needs tocombine soft value bits received during the initial transmission withsoft value bits of redundancy versions for decoding. For a coded blockon which LDPC encoding is performed, to improve decoding performance ofthe communication device at the receive end, a quantity of repeated bitsor skipped bits of the redundancy versions needs to be reduced.

Optionally, the method may further include the following step.

304: Send information indicating the redundancy version sequence.

The communication device 20 may send, to the communication device 21,the information indicating the redundancy version sequence, so that thecommunication device 21 obtains an sequence of starting positions ofredundancy versions for data transmission.

The redundancy version sequence may be indicated by a sequence ofstarting positions, or may be indicated by a sequence of numberscorresponding to starting positions, or each redundancy version sequencemay be numbered and a sequence is indicated by a number. Table 3 showssome examples of correspondences between a plurality of sequences ofstarting positions and redundancy version configuration numbers, andthis is not limited thereto.

TABLE 3 Redundancy Sequence Sequence version rv_(idx) of starting ofstarting sequence index sequence positions in BG1 positions in BG2 0 0,2, 3, 1 0z, 33z, 56z, 17z 0z, 25z, 43z, 13z 1 0, 3, 2, 1 0z, 56z, 33z,17z 0z, 43z, 25z, 13z 2 0, 3, 0, 3 0z, 56z, 0z, 56z 0z, 43z, 0z, 43z 30, 3, 3, 3 0z, 56z, 56z, 56z 0z, 43z, 43z, 43z 4 0, 3, 3, 0 0z, 56z,56z, 0z 0z, 43z, 43z, 0z 5 0, 0, 0, 0 0z, 0z, 0z, 0z 0z, 0z, 0z, 0z 6 0,0, 0, 3 0z, 0z, 0z, 56z 0z, 0z, 0z, 43z 7 0, 0, 3, 3 0z, 0z, 56z, 56z0z, 0z, 43z, 43z 8 3, 3, 3, 3 56z, 56z, 56z, 56z 43z, 43z, 43z, 43z

The information indicating the redundancy version sequence may beindicated by any column in Table 3, that is, the information indicatingthe redundancy version sequence may be an index of the redundancyversion sequence, or may be a sequence of sequences of numbers ofstarting positions, or may be an sequence of starting positions indifferent base graphs, or the like. It may be understood that, it ismerely an example herein, and the present application is not limitedthereto. In a possible implementation, the index of the redundancyversion sequence may correspond to one transmission scenario, or theindex of the redundancy version sequence may be an index of atransmission scenario, to obtain a corresponding redundancy versionsequence based on a transmission scenario.

The communication device 20 may send, via a control channel or a datachannel such as a downlink control channel, a downlink shared channel,or a downlink data channel, the information indicating the redundancyversion sequence. The information indicating the redundancy versionsequence may be carried by physical layer signaling, or may be carriedby higher layer signaling such as radio resource control (RRC)signaling. In this manner, the communication device 20 and thecommunication device 21 may adjust a redundancy version configuration inreal time based on a change in the transmission mode or the servicetype.

For example, the communication device 20 and the communication device 21may initially perform data transmission based on a default redundancyversion configuration, for example, may perform data transmission andretransmission processing based on an sequence of {0, 2, 3, 1}. Ifquality of transmission between the communication devices 20 and 21 orthe service type or the transmission mode changes, the communicationdevice 20 obtains a new redundancy version configuration based on step301, and indicates the new redundancy version configuration to thecommunication device 21 via signaling, so that the communication devices20 and 21 perform transmission based on a new sequence. It should benoted that, this is merely an example herein, and the presentapplication is not limited thereto.

It should be noted that, step 304 is an optional step. In animplementation, the information indicating the redundancy versionsequence may not need to be sent. For example, for a specific servicetype or in a scenario with a specific transmission mode, a particularredundancy version sequence may be predefined or specified in aprotocol. In this case, the communication device 21 learns of theredundancy version sequence by determining the service type or thetransmission mode, so that the communication device 20 may not need tosend the information indicating the redundancy version sequence.

It should be noted that, step 304 may be performed before or after anystep after step 301, and a sequence of step 304 is not specified in thepresent application.

Optionally, after the information processing method is performed, thecommunication device may further process the output bit sequence, sothat the output bit sequence is used during sending or receiving. Forexample, the communication device may perform processing such asinterleaving or mapping into modulated symbols on the output bitsequence. For the processing, refer to a corresponding processing methodin the prior art. Details are not described herein again.

FIG. 4 is a flowchart of an information processing method according toan embodiment of the present application. The method may be applied to acommunication system. The communication system includes a communicationdevice 20 and a communication device 21. The method may be implementedby the communication device 21 and includes the following steps.

401: Determine a redundancy version sequence.

The redundancy version sequence is used to indicate a sequence ofsending a plurality of redundancy versions, and each redundancy versioncorresponds to a starting position in a buffer sequence W.

In a possible design, for the redundancy version sequence, as describedin the foregoing embodiment, the redundancy version sequence may bedetermined based on one or more of the following factors: a servicetype, a transmission mode, or a transmission code rate, and theredundancy version sequence is used to indicate the sequence of sendingthe plurality of redundancy versions. Refer to the descriptions in theforegoing embodiment.

In another possible design, for the redundancy version sequence, theinformation indicating the redundancy version sequence and sent by thecommunication device 20 in step 304 in the foregoing embodiment may bereceived, and the redundancy version sequence is determined based on theinformation indicating the redundancy version sequence. Refer to thedescriptions in the foregoing embodiment.

402: Determine a transmission number.

403: Combine received redundancy versions in a buffer sequence W basedon the redundancy version sequence determined in step 401 and thetransmission number determined in step 402.

The communication device 21 receives a signal sent by the communicationdevice 20. The signal includes a redundancy version corresponding to thebuffer sequence W during a current transmission, namely, the redundancyversion obtained by the communication device 20 from step 303 in theforegoing embodiment.

The communication device 21 demodulates the signal, to obtain a softvalue sequence corresponding to the redundancy version during thecurrent transmission.

A starting position for combination in the buffer sequence W isdetermined based on the redundancy version sequence and a quantity ofcurrent transmissions, and the soft value sequence of the redundancyversion is combined into the buffer sequence W at the starting position.

Optionally, LDPC decoding may be further performed on soft value bits inthe buffer sequence W.

The communication device 21 performs the LDPC decoding on the soft valuebit in the buffer sequence W.

The buffer sequence W includes a soft value sequence of a bit sequence Dor a part of a soft value sequence of a bit sequence D, a length of thesoft value sequence of the bit sequence D is K_(D) bits, and the bitsequence D is a bit sequence obtained by encoding a bit sequence Chaving a length of K based on a low-density parity-check LDPC matrix, orthe bit sequence D is obtained by shortening s₀ bits from a bit sequenceobtained by encoding a bit sequence C having a length of K based on alow-density parity-check LDPC matrix.

The communication device 20 sends the output bit sequence obtained inthe foregoing embodiments to the communication device 21. It may beunderstood that, the output bit sequence in the foregoing embodiments isan output bit sequence obtained after rate matching, and thecommunication device 20 may perform processing such as interleaving andmodulation on the output bit sequence obtained after the rate matching,to send a sending signal corresponding to the output bit sequence. Afterreceiving the output signal and performing demodulation andde-interleaving on the output signal, the communication device 21obtains a soft bit sequence corresponding to the output bit sequence.That is, one bit in the output bit sequence corresponds to one softvalue bit (soft channel bit) in the soft bit sequence. Positions of softvalue bits stored in a soft information buffer of the communicationdevice 21 are in a one-to-one correspondence with locations of codedblocks in a circular buffer of the communication device 20. A size ofthe soft information buffer and a size of the coded block in thecircular buffer are also the same and may be both N_(CB).

For example, an output bit sent by the communication device 20 is 1, andafter channel transmission, the communication device 21 learns that acorresponding soft value bit of the output bit is 1.45, and if aposition of the output bit in the coded block is bit 5, soft value bit 5in the soft information buffer of the communication device 21 is 1.45.It should be noted that, this is merely an example for descriptionherein, and this embodiment of the present application is not limitedthereto. If the output bit sequence obtained by the communication device20 includes n output bits, the communication device 21 may obtain ncorresponding soft value bits. If the communication device 21 receivessoft value bits at a same position at two different times, soft valuesof the soft value bits received at two different times are combined. Forexample, if a soft value bit received during the first transmission is1.45 and a soft value bit received during the second transmission is0.5, 1.95 is obtained after combination. It should be noted that, thisis merely an example herein, and the present application is not limitedthereto.

It can be learned that, the redundancy version sequence has acorresponding feature in the foregoing embodiments. Refer to theforegoing embodiments. Details are not described herein again. It shouldbe noted that, for the communication device 20, the buffer sequence W isa coded block in the circular buffer, and in the communication device21, the buffer sequence W is a soft value sequence in the softinformation buffer. On a side of the communication device 20, an outputbit sequence is determined in the coded block in the circular buffer,and on a side of the communication device 21, a received soft valuesequence is stored in the soft information buffer.

FIG. 5 is a schematic structural diagram of a communication apparatus500. The apparatus 500 may be configured to implement the methoddescribed in the foregoing method embodiment. Refer to the descriptionsin the foregoing method embodiment. The communication apparatus 500 maybe a chip, a base station, a terminal, or another network device.Alternatively, the communication apparatus 500 may be the communicationdevice 20 or the communication device 21 in FIG. 2.

The communication apparatus 500 includes one or more processors 501. Theprocessor 501 may be a general-purpose processor, a dedicated processor,or the like. For example, the processor 501 may be a baseband processoror a central processing unit. The baseband processor may be configuredto process a communication protocol and communication data, and thecentral processing unit may be configured to control the communicationapparatus (such as a base station, a terminal, or a chip), execute asoftware program, and process data in the software program.

In a possible design, the communication apparatus 500 includes the oneor more processors 501, and the one or more processors 501 may beconfigured to implement the method in the embodiment shown in FIG. 3 orFIG. 4. Optionally, the processor 501 may further implement anotherfunction in addition to the method in the embodiment shown in FIG. 3 orFIG. 4, for example, a function of the rate matching module or the ratede-matching module in FIG. 2.

The communication apparatus 500 determines a redundancy versionsequence, where the redundancy version sequence is used to indicate asequence of sending a plurality of redundancy versions; determines atransmission number; and obtains a redundancy version from a buffersequence based on the redundancy version sequence and the transmissionnumber, and sends the redundancy version.

In a possible design, the one or more processors 501 may be configuredto implement the method in the embodiment shown in FIG. 4.

The communication apparatus 500 determines a redundancy versionsequence, where the redundancy version sequence is used to indicate asequence of sending a plurality of redundancy versions; determines atransmission number; and combines received redundancy versions in abuffer sequence based on the redundancy version sequence and thetransmission number. Optionally, the communication apparatus 500 mayperform LDPC decoding on soft value bits in the buffer sequence.

In an optional design, the processor 501 may also include an instruction503, and the instruction may be run on the processor, so that thecommunication apparatus 500 is enabled to perform the methods describedin the foregoing method embodiments.

In another possible design, the communication apparatus 500 may alsoinclude a circuit, and the circuit may implement functions in theforegoing method embodiments. Optionally, the communication apparatus500 may include one or more memories 502, storing an instruction 504,and the instruction may be run on the processor, so that thecommunication apparatus 500 is enabled to perform the methods describedin the foregoing method embodiments. Optionally, the memory may furtherstore data. Optionally, the processor may also store an instructionand/or data. The processor and the memory may be separately disposed ormay be integrated together. Optionally, the one or more memories 502 maystore a parameter or the like related to a starting position and aredundancy version.

In another design, the one or more processors 501 may be configured toimplement the functions of the modules shown in FIG. 2, for example,functions of the modules in the communication device 20 or thecommunication device 21.

Optionally, the communication apparatus 500 may further include atransceiver 505 and an antenna 506. The processor 501 may be referred toas a processing unit, and controls the communication apparatus (aterminal or a base station). The transceiver 505 may be referred to as atransceiver unit, a transceiver, a transceiver circuit, a transceiverinterface, or the like, and is configured to implement sending andreceiving functions of the communication apparatus by using the antenna506, for example, send and receive information indicating the redundancyversion sequence, and send and receive a signal including a redundancyversion.

Optionally, the communication apparatus 500 may further include acomponent configured to generate a transport block CRC, a componentconfigured to perform code block segmentation and CRC check, an encoder,an interleaver used for interleaving, a modulator used for modulationprocessing, or the like. Functions of these components may beimplemented by the one or more processors 501.

Optionally, the communication apparatus 500 may further include ademodulator configured to perform a demodulation operation, ade-interleaver for de-interleaving, a decoder, or the like. Functions ofthese components may be implemented by the one or more processors 501.

Various illustrative logical blocks and steps that are listed in theembodiments of the present application may be implemented by usingelectronic hardware, computer software, or a combination thereof.Whether the functions are implemented by using hardware or softwaredepends on particular applications and a design requirement of theentire system. Various methods may be used to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of theembodiments of the present application.

The various illustrative logical units and circuits described in theembodiments of the present application may implement or operate thedescribed functions by using a general-purpose processor, a digitalsignal processor, an application-specific integrated circuit (ASIC), afield programmable gate array (FPGA) or another programmable logicalapparatus, a discrete gate or transistor logic, a discrete hardwarecomponent, or a design of any combination thereof. The general-purposeprocessor may be a microprocessor. Optionally, the general-purposeprocessor may also be any conventional processor, controller,microcontroller, or state machine. The processor may also be implementedby a combination of computing apparatuses, such as a digital signalprocessor and a microprocessor, a plurality of microprocessors, one ormore microprocessors with a digital signal processor core, or any othersimilar configuration.

Steps of the methods or algorithms described in the embodiments of thepresent application may be directly embedded into hardware, aninstruction executed by a processor, or a combination thereof. Thememory may be a RAM memory, a flash memory, a ROM memory, an EPROMmemory, an EEPROM memory, a register, a hard disk, a removable magneticdisk, a CD-ROM, or a storage medium of any other form in the art. Forexample, the memory may connect to a processor so that the processor mayread information from the memory and write information to the memory.Optionally, the memory may further be integrated into a processor. Theprocessor and the memory may be arranged in an ASIC, and the ASIC may bearranged in UE. Optionally, the processor and the memory may be arrangedin different components of the UE.

With descriptions of the foregoing embodiments, it is understood thatthe present application may be implemented by hardware, firmware, or acombination thereof. When the present application is implemented byusing a software program, all or a part of the present application maybe implemented in a form of a computer program product. The computerprogram product includes one or more computer instructions (which mayalso be referred to as a program or code). When the computerinstructions are loaded and executed on the computer, the procedures orfunctions according to the embodiments of the present application areall or partially generated. When the present application is implementedby a software program, the foregoing functions may be stored in acomputer-readable medium or transmitted as one or more instructions orcode in the computer-readable medium. The computer may be ageneral-purpose computer, a dedicated computer, a computer network, orother programmable apparatuses. The computer instructions may be storedin a computer-readable storage medium or may be transmitted from acomputer-readable storage medium to another computer-readable storagemedium. The computer-readable medium includes a computer storage mediumand a communication medium, where the communication medium includes anymedium that enables a computer program to be transmitted from one placeto another. The storage medium may be any available medium accessible toa computer. The following provides an example but does not impose alimitation: the computer-readable medium may include a RAM, a ROM, anEEPROM, a CD-ROM, or another optical disc storage or a disk storagemedium, or another magnetic storage device, or any other medium that cancarry or store expected program code in a form of an instruction or adata structure and can be accessed by a computer. In addition, anyconnection may be appropriately defined as a computer-readable medium.For example, if software is transmitted from a website, a server, oranother remote source by using a coaxial cable, an optical fiber/cable,a twisted pair, a digital subscriber line (DSL), or wirelesstechnologies such as infrared ray, radio, and microwave, and the coaxialcable, optical fiber/cable, twisted pair, DSL, or wireless technologiessuch as infrared ray, radio, and microwave are included in fixation of amedium to which they belong. For example, a disk used in the presentapplication include a compact disc (CD), a laser disc, an optical disc,a digital versatile disc (DVD), a floppy disk, and a Blu-ray disc, wherethe disk generally copies data by a magnetic means, and the disc copiesdata optically by a laser means. The foregoing combination should alsobe included in the protection scope of the computer-readable medium.

In conclusion, what is described above is merely example embodiments ofthe technical solutions of the present application, but is not intendedto limit the protection scope of the present application. Anymodification, equivalent replacement, or improvement made withoutdeparting from the principle of the present application shall fallwithin the protection scope of the present application.

What is claimed is:
 1. A method for wireless communication, comprising:determining a transmission order of a plurality of redundancy versions,wherein the transmission order of the plurality of redundancy versionsis determined based on a transmission mode, wherein the transmissionmode is grant free; and transmitting one or more of the redundancyversions in the plurality of redundancy versions according to thetransmission order; wherein the redundancy versions in the plurality ofredundancy versions are numbered starting from 0, and the transmissionorder of the plurality of redundancy versions is {0, 3, 0, 3}.
 2. Themethod according to claim 1, further comprising: determining a maximumnumber of retransmission for the plurality of redundancy versions. 3.The method according to claim 2, wherein a total number of transmissionsof the plurality of redundancy versions is less than or equal to themaximum number of retransmission for the plurality of redundancyversions plus one.
 4. The method according to claim 1, wherein eachredundancy version in the plurality of redundancy versions is a bitsequence obtained from a buffered sequence at a starting position,wherein the buffered sequence comprises a quantity N_(CB) of bits from abit sequence D, and wherein the bit sequence D is a low density paritycheck (LDPC) encoded sequence.
 5. The method according to claim 4,wherein a first-transmitted redundancy version is a redundancy version0, and the starting position of the redundancy version 0 is a position 0of the buffered sequence.
 6. The method according to claim 5, whereinwhen N_(CB)=66z; wherein the starting position of redundancy version 1is a position 17z of the buffered sequence; wherein the startingposition of redundancy version 2 is a position 33z of the bufferedsequence; and wherein the starting position of redundancy version 3 is aposition 56z of the buffered sequence; wherein z is a lifting size. 7.The method according to claim 5, wherein N_(CB)=50z; wherein thestarting position of redundancy version 1 is a position 13z of thebuffered sequence; wherein the starting position of redundancy version 2is a position 25z of the buffered sequence; and wherein the startingposition of redundancy version 3 is a position 43z of the bufferedsequence; wherein z is a lifting size.
 8. The method according to claim1, further comprising: repeating transmission of the plurality ofredundancy versions according to the transmission order, until a maximumnumber of repeated transmissions is reached.
 9. The method according toclaim 1, further comprising: obtaining a radio resource control (RRC)signaling via a downlink channel; wherein the RRC signaling carriesindication information of the transmission order of the plurality ofredundancy versions.
 10. A communication apparatus, comprising: at leastone memory; and at least one processor operably coupled to the at leastone memory; wherein the at least one processor is configured to:determine a transmission order of a plurality of redundancy versions,wherein the transmission order of the plurality of redundancy versionsis determined based on a transmission mode, wherein the transmissionmode is grant free; and transmit one or more of the redundancy versionsin the plurality of redundancy versions according to the transmissionorder; wherein the redundancy versions in the plurality of redundancyversions are numbered starting from 0, and the transmission order of theplurality of redundancy versions {0, 3, 0, 3}.
 11. The apparatusaccording to claim 10, wherein the at least one processor is configuredto: determine a maximum number of retransmission for the plurality ofredundancy versions.
 12. The apparatus according to claim 11, wherein atotal number of transmissions of the plurality of redundancy versions isless than or equal to the maximum number of retransmission for theplurality of redundancy versions plus one.
 13. The apparatus accordingto claim 10, wherein each redundancy version in the plurality ofredundancy versions is a bit sequence obtained from a buffered sequenceat a starting position, wherein the buffered sequence comprises aquantity N_(CB) of bits from a bit sequence D, and wherein the bitsequence D is a low density parity check (LDPC) encoded sequence. 14.The apparatus according to claim 13, wherein a first-transmittedredundancy version is a redundancy version 0, and the starting positionof the redundancy version 0 is a position 0 of the buffered sequence.15. The apparatus according to claim 14, wherein N_(CB)=66z; wherein thestarting position of redundancy version 1 is a position 17z of thebuffered sequence; wherein the starting position of redundancy version 2is a position 33z of the buffered sequence; and wherein the startingposition of redundancy version 3 is a position 56z of the bufferedsequence; wherein z is a lifting size.
 16. The apparatus according toclaim 14, wherein N_(CB)=50z; wherein the starting position ofredundancy version 1 is a position 13z of the buffered sequence; whereinthe starting position of redundancy version 2 is a position 25z of thebuffered sequence; and wherein the starting position of redundancyversion 3 is a position 43z of the buffered sequence; wherein z is alifting size.
 17. The apparatus according to claim 10, wherein the atleast one processor is configured to: repeat transmission of theplurality of redundancy versions according to the transmission order,until a maximum number of repeated transmissions is reached.
 18. Theapparatus according to claim 10, wherein the at least one processor isfurther configured to: obtain a radio resource control (RRC) signalingvia a downlink channel; wherein the RRC signaling carries indicationinformation of the transmission order of the plurality of redundancyversions.
 19. A non-transitory computer readable storage medium havinginstructions stored thereon that, when run on a computer, cause thecomputer to perform operations comprising: determining a transmissionorder of a plurality of redundancy versions, wherein the transmissionorder of the plurality of redundancy versions is determined based on atransmission mode, wherein the transmission mode is grant free; andtransmitting one or more of the redundancy versions in the plurality ofredundancy versions according to the transmission order; wherein theredundancy versions in the plurality of redundancy versions are numberedstarting from 0, and the transmission order of the plurality ofredundancy versions is {0, 3, 0, 3}.
 20. The non-transitory computerreadable storage medium according to claim 19, wherein the operationsfurther comprise: determining a maximum number of retransmission for theplurality of redundancy versions.
 21. The non-transitory computerreadable storage medium according to claim 20, wherein a total number oftransmissions of the plurality of redundancy versions is less than orequal to the maximum number of retransmission for the plurality ofredundancy versions plus one.
 22. The non-transitory computer readablestorage medium according to claim 19, wherein each redundancy version inthe plurality of redundancy versions is a bit sequence obtained from abuffered sequence at a starting position, wherein the buffered sequencecomprises a quantity N_(CB) of bits from a bit sequence D, and whereinthe bit sequence D is a low density parity check (LDPC) encodedsequence.
 23. The non-transitory computer readable storage mediumaccording to claim 22, wherein a first-transmitted redundancy version isa redundancy version 0, and the starting position of the redundancyversion 0 is a position 0 of the buffered sequence.
 24. Thenon-transitory computer readable storage medium according to claim 23,wherein N_(CB)=66z; wherein the starting position of redundancy version1 is a position 17z of the buffered sequence; wherein the startingposition of redundancy version 2 is a position 33z of the bufferedsequence; and wherein the starting position of redundancy version 3 is aposition 56z of the buffered sequence; wherein z is a lifting size. 25.The non-transitory computer readable storage medium according to claim23, wherein N_(CB)=50z; wherein the starting position of redundancyversion 1 is a position 13z of the buffered sequence; wherein thestarting position of redundancy version 2 is a position 25z of thebuffered sequence; and wherein the starting position of redundancyversion 3 is a position 43z of the buffered sequence; wherein z is alifting size.
 26. The non-transitory computer readable storage mediumaccording to claim 19, wherein the operations further comprise:repeating transmission of the plurality of redundancy versions accordingto the transmission order, until a maximum number of repeatedtransmissions is reached.
 27. The non-transitory computer readablestorage medium according to claim 19, wherein the operations furthercomprise: obtaining a radio resource control (RRC) signaling via adownlink channel; wherein the RRC signaling carries indicationinformation of the transmission order of the plurality of redundancyversions.